Fumaric acid uses the fumarase enzyme to become malic acid. Malate dehydrogenase catalyzes the conversion of malic acid into oxaloacetate. Two forms of this enzyme exist in eukaryotes. One operates within the mitochondria to contribute to the Citric Acid Cycle; the other is in the cytosol where it participates in the malate/ aspartate shuttle. Riboflavin is an important cofactor for this enzyme and overall mitochondrial energy production and cellular function. At the end of each Citric Acid Cycle, the four-carbon oxaloacetate has been regenerated, and the cycle continues.

Fumaric acid uses the fumarase enzyme to become malic acid. Malate dehydrogenase catalyzes the conversion of malic acid into oxaloacetate. Two forms of this enzyme exist in eukaryotes. One operates within the mitochondria to contribute to the Citric Acid Cycle; the other is in the cytosol where it participates in the malate/ aspartate shuttle.

Riboflavin is an important cofactor for this enzyme and overall mitochondrial energy production and cellular function. Riboflavin (also known as vitamin B2) is one of the B vitamins, which are all water soluble.

At the end of each Citric Acid Cycle, the four-carbon oxaloacetate has been regenerated, and the cycle continues.

Malic Acid is involved in the citric acid cycle (aka. Krebs cycle). The citric acid cycle is a series of reactions that occur in the mitochondrion to generate chemical energy that fuels the metabolism.

Malonic acid is found to be associated with malonyl-CoA decarboxylase deficiency, which is an inborn error of metabolism. The name “Malonic” originates from Latin malum, meaning apple. Malonic acid is the archetypal example of a competitive inhibitor: it acts against succinate dehydrogenase (complex II) in the respiratory electron transport chain. 

Malonic acid is found to be associated with malonyl-CoA decarboxylase deficiency, which is an inborn error of metabolism. The name “Malonic” originates from Latin malum, meaning apple. Malonic acid is the archetypal example of a competitive inhibitor: it acts against succinate dehydrogenase (complex II) in the respiratory electron transport chain. 

Malonic acid is found to be associated with malonyl-CoA decarboxylase deficiency, which is an inborn error of metabolism. The name “Malonic” originates from Latin malum, meaning apple. Malonic acid is the archetypal example of a competitive inhibitor: it acts against succinate dehydrogenase (complex II) in the respiratory electron transport chain. 

Mandelate is a Styrene metabolite.

Sources of exposure:

- Raw materials (benzene and ethylene) for the manufacture of styrene are supplied primarily from the petroleum industry.

- Used in the manufacture of synthetic rubbers, synthetic latex, polyesters, and plastic products.

- Automotive emissions, tobacco smoke, released from building materials, carpet backing. Low-level exposure may occure through ingestion of food products packaged in polystyrene containers.

- Packaging materials, toys, hobbies, crafts, house wares and appliances, electrical and thermal insulation, fiberglass, pipes, automobile parts, foam cups.

- Emissions from styrene production and disposal procedures - chemical spills, landfill sites and industrial discharges.

- Occupational Exposure: industries and operations concerned with the fabrication and application of plastics - styrene/polystyrene manufacturing plants, resin manufacturers, synthetic rubber plants, boats and automobile plants, laminators.

Mandelate + Phenylglyoxylate are Styrene metabolites.

Sources of exposure:

- Raw materials (benzene and ethylene) for the manufacture of styrene are supplied primarily from the petroleum industry.

- Used in the manufacture of synthetic rubbers, synthetic latex, polyesters, and plastic products.

- Automotive emissions, tobacco smoke, released from building materials, carpet backing. Low-level exposure may occure through ingestion of food products packaged in polystyrene containers.

- Packaging materials, toys, hobbies, crafts, house wares and appliances, electrical and thermal insulation, fiberglass, pipes, automobile parts, foam cups.

Mandelic acid is the major metabolite of styrene. Styrene (vinylbenzene) is used as an intermediate in plastic synthesis. Values less than 5 mg/L are due to normal metabolism of phenylalanine or tyrosine.

Mandelic acid is the major metabolite of styrene. Styrene (vinylbenzene) is used as an intermediate in plastic synthesis. Values less than 5 mg/L are due to normal metabolism of phenylalanine or tyrosine.

→ Mandelic acid and benzoylformate are major metabolites of styrene and ethylbenzene exposure.

→ Styrene is a key component in consumer products. Occupational exposure has been associated with increased rates of pulmonary, neurological, genetic, ocular, and reproductive complications, plus leukemia.

→ Styrene can be found in polystyrene packaging and can migrate into packaged food.

→ Benzoylformate has been associated with metabolism of adrenaline and noradrenaline, and phenylketonuria.

→ In a review of 2005–2006 and 2011–2012 NHANES data (N=4690), smokers had 2-fold and 1.6-fold higher levels of both markers.

→ Eating more vegetables and fruit was associated with decreased levels.

- Manganese is an important factor in many critical biochemical processes including antioxidant function.

- Manganese is a mineral element that is both nutritionally essential and has the potential to be very toxic. This fact is further complicated by the small range of dosage for clinical benefit and toxicity with serious consequences.

- The principle antioxidant enzyme within our mitochondria (energy) is superoxide dismutase and the enzymes requires manganese for optimal performance.

- Manganese is also required for normal skeletal development and cartilage synthesis.

- Wound healing is also impacted by manganese, as the synthesis of collagen in skin cells is dependent on the presence of adequate manganese.

- Manganese is also important functioning as a co-factor in the metabolism of carbohydrates, amino acids and cholesterol.

- Manganese is considered anti-osteoporotic and anti-arthritic.

Fecal manganese (Mn) provides an indication of recent oral exposure to the element, and to a much lesser extent Mn that has been excreted from the body in bile. Manganese is an essential trace element that is naturally present in many foods and available as a dietary supplement. Oral absorption is very low (< 3%), so the vast majority of fecal Mn represents unabsorbed Mn from foods and beverages. Low oral absorption is protective because excessive retention of Mn in the body may have neurological consequences.

Manganese, a trace element found in whole blood, plays a pivotal role in human health and is measured in a Toxic and Essential Elements panel. As an essential nutrient, manganese is crucial for several biological processes, including bone formation, blood clotting, and immune response. It acts as a cofactor for various enzymes, notably those involved in metabolism and antioxidant defenses, such as superoxide dismutase, which protects cells from damage caused by free radicals. Despite its essentiality, manganese levels must be tightly regulated, as both deficiency and excess can lead to health issues.